Sharif, Abdulrahman A., et al. “On Existence and Uniqueness of Solutions to a Class of Fractional Volterra-Fredholm Initial Value Problems”. Discontinuity, Nonlinearity, and Complexity, vol. 12, no. 4, Aug. 2026, pp. 905-16, https://doi.org/10.5890/DNC.2023.12.014.